Last updated: 02/17/2009

Hemorrhoids are a fairly common problem among adults in the United States and Canada; it is estimated that ten million people in North America, or about 4% of the adult population, have hemorrhoids. About a third of these people seek medical treatment...

in an average year; nearly 1.5 million prescriptions are filled annually for medications to relieve the discomfort of hemorrhoids. Most patients with symptomatic hemorrhoids are between the ages of 45 and 65.

Risk factors for the development of symptomatic hemorrhoids include the following:

• hormonal changes associated with pregnancy and childbirth
• normal aging
• not getting enough fiber in the diet
• chronic diarrhea
• anal intercourse
• constipation resulting from medications, dehydration, or other causes
• sitting too long on the toilet

Hemorrhoids are categorized as either external or internal hemorrhoids. External hemorrhoids develop under the skin surrounding the anus; they may cause pain and bleeding when the vein in the hemorrhoid forms a clot. This is known as a thrombosed hemorrhoid. In addition, the piece of skin, known as a skin tag, that is left behind when a thrombosed hemorrhoid heals often causes problems for the patient's hygiene. Internal hemorrhoids develop inside the anus. They can cause pain when they prolapse (fall down toward the outside of the body) and cause the anal sphincter to go into spasm. They may bleed or release mucus that can cause irritation of the skin surrounding the anus. Lastly, internal hemorrhoids may become incarcerated or strangulated.